Wrong - not cardiac tamponade.
Why did you choose this? If it was because you believed some of the symptoms suggested a restrictive cardiac problem, then you were partly right because a restrictive problem did contribute to the patient's demise; however, the absence of any blood in the pericardial sac doesn't really support your choice.
What else could cause a physical restriction of myocardial movement? And why was the myocardium pale and firm to the touch?